Clean up cache module; affects [feedz jenkinsplugin myget node nuget packagist travis wordpress] (#7319)

* update terminology
    - "regular update" to "cached resource"
    - "interval" to "ttl"
    - move file and update imports

* set a default TTL, don't explicitly pass params if we want the default

* add tests

* update docs

services/node/node-version-color.js

@@ -1,6 +1,6 @@
 import moment from 'moment'
 import semver from 'semver'
-import { regularUpdate } from '../../core/legacy/regular-update.js'
+import { getCachedResource } from '../../core/base-service/resource-cache.js'
 
 const dateFormat = 'YYYY-MM-DD'
 
@@ -9,9 +9,8 @@ async function getVersion(version) {
   if (version) {
     semver = `-${version}.x`
   }
-  return regularUpdate({
+  return getCachedResource({
     url: `https://nodejs.org/dist/latest${semver}/SHASUMS256.txt`,
-    intervalMillis: 24 * 3600 * 1000,
     json: false,
     scraper: shasums => {
       // tarball index start, tarball index end
@@ -36,10 +35,8 @@ async function getCurrentVersion() {
 }
 
 async function getLtsVersions() {
-  const versions = await regularUpdate({
+  const versions = await getCachedResource({
     url: 'https://raw.githubusercontent.com/nodejs/Release/master/schedule.json',
-    intervalMillis: 24 * 3600 * 1000,
-    json: true,
     scraper: ltsVersionsScraper,
   })
   return Promise.all(versions.map(getVersion))